Cam locked up in head

[Sandm849]

That's what I thought. Amazingly I've had 8 festivas and this is my first carb.

[FB71]

Ok so by what everybody has seen I should just be able to put a head on and be good to go?

a TSB from '89 or '90 indicated that cam siezure is most likely due to lack of oil delivery to the outer cam journals, due to sludge build-up inside the rocker shafts.

The rocker shafts carry oil from the feed passge in the center journal to the outer journals. If the shafts become clogged with sludge, the outer journals will experience oil starvation. The material the head is cast in is prone to galling and fretting, as indicated in the TSB.

If cam siezure occures, the rocker shafts should eith er be cleaned, by removing the core pluggs at either end and rodding, or replacement.

[Pu241]

FB71, any suggestions on what to use to flush out sludge on vehicles that may have had poor maintenance or may have sat for an extended time.
I'm thinking seafoam, trans fluid, or diesel fuel; in controlled amounts, < 1/2 quart, in the oil just before changing it. Let it idle, no driving on diluted oil, and drain it.
The other option is to just change the oil when it gets dirty and not wait for 3K miles.
Just thinking, a lot of festivas that are being put back on-line are likely to need some sort of "cleaning out".

[resuwrecked]

^breaking junk loose inside your engine causing it to lodge in other places. Dont do anything unless youre having problems already.

[grey]

No, I'd prefer you understand that in unmodified B3 and B6 engines that piston valve contact is NOT possible.
I'm not certain that even if you shaved the head to the point you'd get contact that you'd have a running engine as the compression ratio could well be too high for pump gas.
You may well be correct on other engines, but not on these.

I have one here already taken apart to look at. Valves can hit pistons.

[Pu241]

Then please post pics, as I have never seen nor have there been any reports on this site that anyone has had valve or piston damage due to a failed timing belt.

[Pu241]

^breaking junk loose inside your engine causing it to lodge in other places. Dont do anything unless youre having problems already.

I see your point!
But, I can also see crud breaking loose and lodging in critical areas, if it isn't dissolved/broke-up in to smaller particles to be filtered or drained from system.
Especially, from engines that have been setting for months maybe years unused.
Which seems to be the case more often of late.
I can also see that some of these "flushing" materials can cause already dried out seals to fail as well.
So maybe just decreasing the interval of oil changes might be best.

[grey]

Then please post pics, as I have never seen nor have there been any reports on this site that anyone has had valve or piston damage due to a failed timing belt.

so you will remember the lesson, I suggest you go over to your own car and loosen the T belt. Now advance the cam about half turn and put the belt back on. Now crank the engine.

That will help you to learn what the term "interference engine" does not mean.



----------------

If you have a head and block apart to look at, this is obvious.

Pictiures? I will save the bandwidth for more important things

[Zanzer]

I see your point!
But, I can also see crud breaking loose and lodging in critical areas, if it isn't dissolved/broke-up in to smaller particles to be filtered or drained from system.
Especially, from engines that have been setting for months maybe years unused.
Which seems to be the case more often of late.
I can also see that some of these "flushing" materials can cause already dried out seals to fail as well.
So maybe just decreasing the interval of oil changes might be best.

That's how I typically do it if I get one that has crud built up in it. I'll run the oil for 1000-1500 miles and then drop it and the filter. Then it's basically "rinse and repeat" with new oil and filter until she comes clean. Also, I found that substituting in 1/2 - 1 quart of Marvel Mystery Oil helps too...especially if you're having trouble with valve train components like lash adjusters.

[Pu241]

How about I come over to your place and you teach me the lesson first hand so you can bask in the glow of you being right.
Provided you are!
Oh, I see your not only too lazy to post pics to prove your point and perhaps help other people learn here.
But your too lazy to post your location.
Hey, don't worry about the bandwidth I and every other donor to this site helps pay for it.
So feel free to use some of it to illustrate your point, if you can.
I just don't happen to have a head and block apart at this time, since you do, make use of it.

[grey]

I dont know who you were talking to about belt breaking, but i never mentioned it. It was not in the original post either.

My point was that there is very little room to play with between valve and piston. That is why most "How-to" guides say rotate the engine with a wrench after chanking belts. If the one here does not.... then it should.

[grey]

I just don't happen to have a head and block apart at this time, since you do, make use of it.

I did, but you either cant or wont listen.

"interference engine " is an ASE (or some other engineer society) term. It should not be hard to find a definition

[Pu241]

Hey, I'm wasting timing replying to your posts, so clearly I listen to a certain extent.
But, your right it wasn't too hard to find a definition.
How about this:

http://en.wikipedia.org/wiki/Mazda_B_engine

Specifically, this part:
"Mazda B-series is a "non-interference" design, meaning that breakage of its timing belt does not result in damage to valves or pistons, because the opening of the valves, the depth of the combustion chamber and (in some variants) the shaping of the piston crown allow sufficient clearance for the open valves in any possible piston position."

[Sandm849]

Nice useage of wikipedia. ^^^. I'm tired of hearing about this! There is the definition! Case closed!!

[Sandm849]

And thanks for the good old ford info Jim!